Addiction to morphine and heroin can be blocked, according to research released Wednesday which could prove a major breakthrough in treating addicts and in pain relief treatments.

Researchers at the University of Adelaide in Australia worked with colleagues at the University of Colorado in the United States to pinpoint a key mechanism in the body's immune system that amplifies addiction to opioid drugs.

Guatemalans who had been subjected to sexually transmitted diseases by U.S. researchers in the 1940s have appealed a judge's dismissal of their lawsuit.

U.S. District Judge Reggie Walton dismissed the suit two months ago. He ruled that federal law bars claims against the U.S. based on injuries suffered abroad. The victims filed an appeal Monday with the U.S. Court of Appeals in Washington.

Drugmakers AstraZeneca PLC and Pfizer Inc. have reached a deal giving Pfizer future rights to sell a nonprescription version of AstraZeneca's blockbuster heartburn drug, Nexium, as early as 2014.

The deal, announced late Monday, could help Pfizer expand its consumer-health business as it continues a restructuring meant to strengthen its core drug business and divest its infant-formula and animal-health businesses. The companies said they're exploring the idea of a partnership to convert other AstraZeneca prescription drugs to over-the-counter medicines.

Swiss pharma giant Roche said Monday it will sell in the United States a drug that treats a diabetes-related illness linked to blindness after getting the regulatory green light.

The U.S. Food and Drug Administration's (FDA) decision means that Roche can take Lucentis to the U.S. to treat diabetic macular oedema (DME), a condition that causes swelling, blurred vision and blindness in people with diabetes.

A recent outbreak of the deadly Ebola virus is "under control" but has not yet been fully eradicated, a Ugandan health official said Monday.

Two suspicious cases were admitted to a hospital close to the scene of the outbreak over the weekend, bringing to nine the total number of people currently in isolation, the official said.

Nepal on Monday urged foreign travellers to take precautions against cholera after 13 people died in an outbreak in the remote west of the country.

Visitors were urged by GD Thakur, director of the Himalayan nation's epidemiology and disease control department, to drink boiled or mineral water and "pay attention to their personal care and hygiene".

U.S. laws strictly curbing school sales of junk food and sweetened drinks may play a role in slowing childhood obesity, according to a study that seems to offer the first evidence such efforts could pay off.

The results come from the first large U.S. look at the effectiveness of the state laws over time.

The Health Ministry says bird flu has killed a 37-year-old man in central Indonesia, marking the country's ninth fatality this year.

The Ministry's website said Monday that the man died July 30 in Yogyakarta province after being hospitalized for five days.

Behind air-tight doors in a lab in a southern French city, scientists in protective coveralls wage war against a fingernail-sized danger.

Lurking in net cages is their foe: the Asian tiger mosquito, capable of spreading dengue fever and other tropical diseases in temperate Europe.

That's the message state and county fair visitors got Thursday from health officials who reported a five-fold increase of cases of a new strain of swine flu that spreads from pigs to people. Most of the cases are linked to the fairs, where visitors are in close contact with infected pigs.

This flu has mild symptoms and it's not really spreading from person to person.